import React, { Component } from 'react'
import './Footer.css'

export default class Footer extends Component {

  //全选check的回调
  handleCheckAll = (event)=>{
    this.props.checkAllTodo(event.target.checked)

  }

  //删掉已完成的回调
  handleClearAll = ()=>{
    this.props.clearAll()
  }

  render() {
    const {todos} = this.props
    const total = todos.length
    const doneCount = todos.reduce((pre,current) => pre + (current.done ? 1 :0 ),0)

    return (
      <div className="todo-footer">
        <label>
          <input type="checkbox" checked={doneCount === total && total !== 0 ? true : false} onChange={this.handleCheckAll}/>
        </label>
        <span>
          <span>已完成{doneCount}</span> / 全部{total}
        </span>
        <button onClick={this.handleClearAll} className="btn btn-danger">清除已完成任务</button>
      </div>
    )
  }
}
